FR2504908A2 - PROCESS FOR THE PREPARATION OF ALUMINUM OR MAGNESIUM PHOSPHIDE - Google Patents

Abstract

A.PROCESS FOR THE PREPARATION OF ALUMINUM OR MAGNESIUM PHOSPHIDE. B. PROCESS CHARACTERIZED IN THAT YELLOW PHOSPHORUS IN LIQUID FORM AS WELL AS FINALLY DIVIDED METAL ARE SLOWLY ADDED INTO THE REACTION VASE. C. THE INVENTION APPLIES TO METHODS FOR THE PREPARATION OF ALUMINUM OR MAGNESIUM PHOSPHIDE.

Description

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  The main patent (Application No. 8020966) relates to a process for the preparation of aluminum or magnesium phosphide, in which the metal or an alloy of the two finely divided metals is reacted with the phosphorus at a temperature between 300 and 600 OC, in an atmosphere of inert gas and in the presence of a catalyst, of bromine, iodine or a compound of the abovementioned elements with phosphorus, sulfur, hydrogen, ammonium, zinc or

  metal to react with yellow phosphorus.

  According to a particular embodiment

  The finely powdered or fine-grained metal is intimately mixed with the catalyst. The mixture in a suitable reaction vessel, which can be closed, is heated under an inert atmosphere, for example, nitrogen, at ambient pressure, at room temperature. reaction temperature

between 300 and 6000 c.

  However, it has been discovered that it is possible to carry out the method according to the main patent in an even safer, easier to control and especially partially or even completely continuous way, by a modification of the process which also involves introducing the metal. finely

  slowly divided in the reaction vessel.

  Accordingly, the process according to the invention is characterized in that the yellow phosphorus in liquid form as well as the finely divided metal are added

  slowly in the reaction vessel.

  If the process according to the invention is carried out in a substantially cylindrical reaction vessel, which is heated by the bottom bottom, four distinct zones are formed, which can be described starting from the

up as follows.

  1st zone: In this upper zone, there is only gas, namely a mixture of inert gas and phosphorus vapor As in this zone, in an extreme case, a temperature not exceeding about 200 C is reached, the vapor pressure of the phosphorus is relatively low, so that the gas mixture is mainly constituted

by the inert gas used.

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2nd zone:

  This is the vaporization zone of the phos-

  In this zone, there is a temperature slightly higher than the boiling point of the yellow phosphorus. In this zone there is also only gas, but here it is constituted

  mainly phosphorus vapor.

  3rd zone Here is located in the upper layer of filling of the vessel, the actual reaction zone where the phosphorus vapor comes into contact with the finely divided metal and with the phosphide already formed In this zone which is at the reaction temperature between 300 and 6000 C, the reaction strongly exothermic

  between phosphorus vapor and finely divided metal.

  As phosphorus vapor reacts very quickly with metal, it does not penetrate very deeply inside

  filling the vase, but only about 10 to 15 cm.

  Inside the filling, the gaseous phase becomes poorer

  very quickly up and down in phosphorus vapor.

  4th zone: In this lower zone, the gaseous phase is still composed mainly of inert gas

  because the phosphorus vapor does not penetrate to this depth

  The solid material consists practically only of the phosphide formed and in any case contains only small quantities of unreacted metal.

  to ensure that the phosphide formed is free of phosphorus.

  The formation inside the reaction vessel of the four zones described above makes it possible to carry out the process in a particularly simple and completely safe form. The liquid yellow phosphorus is introduced here continuously into the upper part of the reaction vessel, hence into the volume. gaseous above the filling, where it can vaporize

without obstacle.

  It is particularly advantageous that the inlet for the liquid phosphorus is found while

  top of the reaction vessel, that is to say in the upper zone 1.

  The finely divided metal can also be introduced into the upper part of the reaction vessel. However, the rapid and violent reaction with the phosphorus vapor already present in high concentration requires the use of a special closure member. of the inlet to prevent the penetration of phosphorus vapor into the organ where the metal arrives

finely divided.

  It is therefore more advantageous to introduce the finely divided metal continuously in the lower part

  of the reaction vessel and this so that the opening orifice

  This can be done in the third zone, that is to say in the reaction zone itself. It is then advantageous to provide at the height of the introduction orifice. metal, a mixing element which ensures the advancement of the load along the walls of the vessel and thus ensures a uniform distribution of the freshly introduced metal in the reaction zone It is even more advantageous that the introduction of the finely divided metal s performs in the lower part of the vase

  reaction, that is to say in the fourth zone.

  In this case, it is advantageous to provide an agitator whose elements advance the load along the walls of the vessel and at the same time ensure vertical mixing of the feed.

  in the reaction vessel continuously

  valences of finely divided metal in which the catalyst is melanated, and liquid yellow phosphorus and to evacuate during the reaction the phosphorus-free formed phosphide reacted from the lower part of the reaction vessel, the fourth zone It can be carried out continuously by means of separate charges. If the sampling is continuous, the product is withdrawn in a corresponding quantity to the metal and phospho introduced continuously. the phosphide accumulate in the lower zone of the vessel, ie the fourth zone, and then remove the phosphide formed by separate charges.

  to extract from this fourth zone only material which does not

  no unreacted phosphorus, and not the material of the reaction zone, which can be

weight control.

  If the finely divided metal is intr as described above, in the lower part of the vase

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  reaction, ie the third and fourth zones, then a simple conveyor screw suffices as a metering member, because the solid charge in fine grains serves almost as a shutter element When the method according to the invention is started in a vacuum, it is therefore advantageous to introduce at first only finely divided metal, until the metal introduction orifice is covered, and then begin the gradual introduction of the liquid phosphorus. even more advantageous, fill the vessel first up to the top of the metal introduction port, with appropriate phosphide from a production

  previous year, and then undertake the introduction

  production of finely divided metal and liquid phosphorus.

  The invention will be better understood from the examples below. All percentages are

  given by weight, unless otherwise indicated.

Example 1

  The reaction vessel used is a cylindrical vessel having a diameter of about 80 cm and a height of about 100 cm, equipped with an agitator, a cooling system, temperature sensors at different

  levels, an inert gas supply and an evacuation

  cuation The bottom of the vessel can be heated from the outside by a gas burner at a temperature up to 500 'C. A tank for the liquid yellow phosphorus is connected with a pump which can be used as the case may be. circulate the liquid yellow phosphorus in this tank or to introduce it into the reaction vessel, as well as a tank for the finely divided metal to react, with a dosing device for the introduction of the metal into the vase at the bottom of the vase there is a small hole with a shutter element, for the evacuation of the product For security reasons, the vase is equipped with a bursting disk to prevent a possible rise in pressure The vase is rinsed with the nitrogen before and after the reaction and during the reaction, the mixture is kept under argon atmosphere The gas is discharged through a water bubbler with a fiberglass filter and an activated carbon filter

connected downstream.

  Before the start of the reaction, the vessel contains 50 kg of magnesium phosphide from a previous production, in the metal tank a 2 z-04908 mixture of 200 kgs of magnesium and 0.8 kg d iodine and in the liquid phosphor tank, it is kept in circulation The vessel is then heated by the bottom to 3000 C. 10 kg of magnesium are then introduced into the vessel and the introduction of the liquid phosphorus with a speed from 0.4 to 1 kg per minute The heat released by the reaction raises the temperature in the lower part of the vessel to 550 C. The introduction of phosphorus and magnesium is then adjusted so as to maintain the temperature at 5500 C, and the weight ratio between phosphorus and magnesium, around 0.85: 1 When about 180 kgs of magnesium phosphide were formed in the vessel, 100 kgs were evacuated within 10 minutes. product through the evacuation port, while pursuing the introduction of phosphorus

  and metal The vent hole is again contained.

  When another 180 kg of magnesium phosphide is formed again, it is evacuated again, and finally, these operations are repeated once more. After the consumption of 200 kg of magnesium, the introduction of phosphorus is stopped. product still in the vase is still heated for a short period of time and then discharged. By counting the magnesium phosphide: deposited in the vase, 4.5 hours were removed in 4.5 hours.

  of product with a 92% content of magnesium phosphide.

Example 2

  In the vessel of Example 1, a mixture of 100 kgs of magnesium and 0.3 kg of iodine is prepared, in the metal tank, there is a mixture of 150 kgs of magnum 0.5 kg of magnesium. iodine The vessel is then heated by the bottom at 301 Then begins to introduce the phosphorus so as to gradually raise the temperature in the lower part of the container to 550 c This temperature is then maintained by adjusting the rate of introduction of phosphorus, until At a total consumption of 82 kgs of phosphorus, magnesium and phosphorus are introduced at the same time into a ratio of 1: 0.83, at a rate which makes it possible to maintain the temperature in the lower part of the vessel, between 500 and 5501 C The product is evacuated at the same time through the evacuation orifice so that the quantity evacuated corresponds exactly to the quantity of magnesium and phosphorus introduced, ie all 150 kgs of magnesium and 123 kgs of phosphorus. still heating e for a short time the product is found

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  still in the vase, and continues the evacuation continuously.

  The yield amounts to 450 kg with an average

% magnesium phosphide.

Example 3

  In the vessel described in Example 1, there is a mixture of 50 kg of fine-grain aluminum-magnesium alloy with a magnesium content of 5% and 0.2 kg of iodine; in the metal tank, a mixture of kgs of the mentioned alloy and 0.6 kg of iodine is prepared. The bottom of the vessel is heated to 450 ° C. The introduction of the phosphorus and the alloy is begun. the phosphorus is introduced at a relatively high speed, in order to balance the excess of alloy, until a ratio by weight of phosphorus to the alloy of 1.1: 1 is maintained. a temperature of 500 ° C. is obtained in the interior of the vessel. The phosphorus and the alloy are then introduced in a weight ratio of 1.1: 1, until the vessel contains about 1 kg of product. at this moment, the product is withdrawn through the continuous discharge orifice, at the same rate as the phosphorus and the alloy are introduced. The introduction is adjusted.

  so that the temperature does not exceed 5501 C After consumption

  tion of all the alloy, we stop the introduction of phosphorus, the heating is restarted and the rest of the product is evacuated, always continuously We obtain in all 520 kgs of a

  granular product with a phosphorus content of 90%.

Exemple 4.

  In the vessel described in Example 1, 130 kgs of aluminum phosphide of a previous production are placed in place, and in the metal tank, a mixture of 250 kg of aluminum and 1 kg of iodine is heated. the vessel at the bottom at 480 ° C. and 20 kgs of aluminum are introduced. Aluminum and phosphorus are then introduced simultaneously when the temperature reaches 500 ° C., the heating is stopped. The excess of metal is

  balanced by accelerated phosphorus

  The ratio of aluminum and phosphorus is continued in a ratio of 1: 1.1 at a rate such that the temperature does not exceed 570 ° C. In the vessel there is a total of 230 kg of product. evacuates 130 kg while continuing the introduction of phosphorus and aluminum This process

  is reiterated until consumption of 250 kg of aluminum.

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  A total of 501 kgs of product with an aluminum phosphide content of 95% are discharged and approximately 155 kgs are left behind.

  of product in the vase for the next operation.

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Claims (1)

  1) A process for the preparation of aluminum or magnesium phosphide, in which the metal or an alloy of the two finely divided metals is reacted with yellow phosphorus at a temperature of between 300 and 600 ° C. in an atmosphere of inert gas and in the presence, as a catalyst of chlorine, bromine, iodine or a compound of the elements mentioned with phosphorus, sulfur, hydrogen, ammonium, zinc or the metal to be reacted with yellow phosphorus, according to application 80 20 966, characterized in that yellow phosphorus in liquid form as well as finely divided metal   are slowly added to the reaction vessel.   Process according to Claim 1, characterized in that the liquid yellow phosphorus is introduced into the upper part of the reaction vessel, so that the introduction orifice is above the level of filling of the reaction vessel with the reaction mixture and the products of the reaction.   Method according to one of the claims   1 or 2, characterized in that the finely divided metal is introduced into the lower part of the reaction vessel, so that the introduction orifice is in the filling zone of the reaction vessel with the reaction mixture and the products of the reaction.